Mechanism for clamping and releasing weft yarn



Oct. 4, 1966 R. B. GOLOBART 3,276,483

AND RELEASING WEFT YARN MECHANISM FOR CLAMPING 2 Sheets-Sheet 1 Filed Sept. 16, 1964 Oct. 4, 1966 R. B. GQLOBART 3,276,433

MECHANISM FOR CLAMPING AND RELEASING WEFT YARN Filed Sept. 16, 1964 2 Sheets-Sheet 2 United States Patent 3,276,483 MECHANISM FOR CLAMIHNG AND RELEASING WEFT YARN Ramon Balaguer Golobart, Calle Caspe 86, Barcelona, Spain Filed Sept. 16, 1964, Ser. No. 396,941 Claims priority, application Spain, Sept. 19, 1963, 291,992

' 3 (Ilaims. (Cl. 139122) This invention relates to a device for clamping and releasing weft yarn and in particular to such a device for use in a shuttleless loom.

The systems used in shuttleless looms for clamping the weft yarn, in order that the same may be cut, then drawn by the weft-inserting member through the shed in consecutive picks to form a fabric, have not satisfactorily solved the problem of co-operation with weft yarns of different kinds-Le, problems connected with the fact that the weft yarns come in a wide variety of thicknesses and strengths. Often, special yarns made wholly or partly of synthetic fibres, and weft yarns formed by plastics, require considenable clamping in order to prevent their slipping when the vice of the weft-inserting member pulls the out weft through the shed. The result of the weft yarn slipping is that it is not inserted into the shed. The same disadvantage occurs in connection with fabrics made up of a widely differing variety of weft yarn-i.e., because the weft yarns differ in thickness from one another or because they may be of completely different kinds from one another. For instance, cotton-fibre weft yarns may be associated with weft yarns wholly or partly of some other kind, such as synthetic yarns or yarn made completely from plastics which yarns require an immediate opening and closure of the vice of the weft-yarn gripper. There are of course weft-clamping vices whose clamping can be adjusted to suit different qualities or thicknesses of weft yarn; unfortunately, the adjustment is not automatic and so these known vices cannot be used to produce outof-run fabrics. Another disadvantage of the known systems is that they take up considerable space and it is therefore difficult to find room for them on the loom since available space is limited.

According to the present invention the jaws of the weftclamping vice are provided with a closure system similar to a scissors action, the two levers of the scissors being fitted with two plates resembling vice jaws, the jaws clamping the weft yarn, when closed, at exactly the time required for the yarn to be cut by any known means, immediately whereafter the jaws open to release the weft yarn in order that the weft-inserting member may pull the same through the shed.

The closure provided, although giving firm clamping, is resilient enough to suit any kind of weft yarns used in weaving without the need for any readjustment. The two members which form the vice may be disposed opposite one another and the jaw-bearing levers may share the same fulcrum just like scissors, one jaw or the like being movable and the opposite jaw being stationary, the stationary jaw being secured to a stationary part of the loom in a substantially horizontal position for correct adaptation of the weft yarns; and when a closure-i.e., the clamping of the weft yarn-is required, the moving top arm of the system provides the clamping action by a scissors-like rotation on to the opposite stationary arm of the device, to grip the weft yarn with the optimum pressure thanks to the action of a rod connected to the end of the bottom part of a movable lever or the like of the vice. The movement for instantaneously opening and closing the jaws forming the vice may be produced by a reciprocation of the rod which communicates to the moving member of the vice, from the bottom end of the jaw- "ice bearing lever whose bearing zone is stressed by means of a helical retaining spring to balance the pressure required by each thickness of kind of weft yarn, to provide, without the need for any other readjustment, an automatic clamping of the weft yarn which is always correct. The cam shape leaves completely free an appropriate roller disposed at the end of the bottom arm of the transmitting lever which serves as a bearing at the end of the top arm for the rod; and when such roller is released from the action of the cam at a particular time, such roller produces the instantaneous closure movement of the moving member of the vice system, to thus clamp the weft yarn. Immediately a projecting slideway of the cam passes by, it raises the bottom arm of the rod-operating lever to produce the instantaneous opening of the moving member of the vice system to release the weft yarn.

According to another feature of the invention, in some cases the lever transmitting the reciprocation to the rod may take the form of two arms resiliently interconnected by a helical spring disposed around the bearing spindle, which assembly forms in itself the actual transmitting lever, but the top arm thereof connected to the rod transmits the force resiliently to its bearing position which, being connected with the bottom anm receiving the movement of the cam, causes the moving member to open and close consecutively but without any abrupt impact likely to damage some of the weft yarns used in textiles.

Since the transmission is preferably by means of a cylindrical rod which can be shaped just as required to suit the distances when the system is positioned, the mechanism can readily be fitted without any need for additions or extra spindles, since any spindle at the front of the loom can be used.

One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which,

FIGURE 1 is a view in side elevation of an embodiment of the device with the vice jaws open to release the weft yarn;

FIGURE 2 is a view in side elevation of the device with the vice jaws closed and clamping a weft yarn;

FIGURE 3 is a front view, looking in the direction indicated by an arrow A in FIGURE 2, with the vice jaws closed and clamping a weft yarn, and

FIGURE 4 is a view on an enlarged scale of a detail connected with the other drawings and showing one possible modification of the transmission lever.

Referring to FIGURES 1-3, a fixed sheet-metal lever 1 is connected to any part of a loom (not shown) by way of its top arm 2 and a screw or the like 3; secured to bottom arm 4 of the lever 1 is a plate or the like 5 adapted to form a stationary jaw of i3. vice. A movable lever 7 is pivotally mounted on the fixed lever 1 by means of a pivot 6 and has fitted to its end 8 a plate 9 forming a moving jaw of the vice, said jaw plates 5 and 9 may be of steel, nylon or any other suitable material. A transmission rod 12 is pivotally connected by a pivot 11 to the other end of the bottom portion 10 of the moving lever 7; the rod 12 has provision for vertical adjustment at its bottom end 13 in the form of a collar 14 and clamping screw 15. The collar 14 is pivoted to end 16 of top arm 17 of a transmission lever 18 rockable around a spindle 19; thnough the agency of a helical spring 20 ad justed by a collar 21 secured by a screw 22, a constant pressure to close the moving jaw 9 of the vice is applied via the bottom anrn 23 of the transmitting lever 18 said arm 23 has a roller 24 at its end and is reciprocated by a cam 25 rotating on a rotating spindle 26 of the loom; a projecting s-lideway 27 extends from the cam 25 and is adapted to raise the bottom arm 23 of the lever 18 to a open the moving jaw 9 of the vice in order that a weft yarn 28 may be introduced thereinto.

Referring to FIGURE 4, the top arm 17 and bottom arm 23 which form the lever 18 are firmly but flexibly interconnected by means of a spiral spring 29 whose bent end 30 is introduced into an aperture 31 in a bearing 32 for the bottom arm 23, the bearing 32 being associated with the spindle 33, while the other bent end 34 of the spring 29 is introduced into an aperture 35 in a bearing 36 in the top arm 17, the bearing 36 being associated with the spindle 33; the entire system is loaded by a helical spring 20 which acts like a Growers washer to interconnect the two arms 17, 23, which form the transmission lever, by a collar 21 and a locknut 37.

A device constructed as described above has been found to be advantageous over known devices in obviating many problems caused by the wide variety of weft yarns now used; the known mechanisms do not solve such problems satisfactorily.

Such a device has been found to be mechanically very simple and rugged and takes up little space, the latter feature being very useful since in modern looms, which have a large number of devices and attachments, it is really difficult to find a free space for a new mechanism without interfering with the remainder.

What I claim is:

1. In a weft clamping and releasing device for looms which comprises a pair of cooperating jaws arranged opposite each other, one of said jaws being stationary and secured to a stationary part of the loom in substantially horizontal position, the other of said jaws being movable and pivotally linked to said stationary jaw in a scissorslike manner, rotating cam means, rocking lever means actuated by said cam means, and reciprocating rod means operatively connecting said rocking lever means and said movable jaw, the improvement wherein said lever means comprises a bearing spindle, two cooperating lever arms supported on said spindle, first helical spring means disposed around said bearing spindle and resiliently interconnecting said t-wo arms, and second helical spring means disposed around said bearing spindle, said second spring means being connected to one of said arms, said one arm being actuated in one direction by the movement of said cam means and in the opposite direction by said second helical spring means, the other of said arms being connected to the said reciprocating rod means for transmitting the movement to said movable jaw and so causing consecutively the closing and opening of the device for resiliently clamping and releasing the weft.

2. A device as claimed in claim 8 comprising a projecting slideway on said cam means actuating said lower lever arm.

3. A device as claimed in claim 9 wherein said second spring means is adjustably fixedly mounted on said rod.

References Cited by the Examiner UNITED STATES PATENTS 1,102,610 7/1914 Stahl 139-375 1,746,465 2/1930 Gabler 139127 2,489,849 11/1949 Bahan 139--3 46 2,553,351 5/1951 Belotti 139-127 2,749,946 6/1956 Pfarrwall er 139126 2,785,701 3/1957 Dunham 139347 2,819,736 1/1958 Pfarrwaller 139-126 3,181,569 5/1965 Carroll 139122 MERVIN STEIN, Primary Examiner.

DONALD W. PARKER, Examiner.

H. S. JAUDON, Assistant Examiner. 

1. IN A WEFT CLAMPING AND RELEASING DEVICE FOR LOOMS WHICH COMPRISES A PAIR OF COOPERATING JAWS ARRANGED OPPOSITE EACH OTHER, ONE OF SAID JAWS BEING STATIONARY AND SECURED TO A STATIONARY PART OF THE LOOM IN SUBSTANTIALLY HORIZONTAL POSITION, THE OTHER OF SAID JAWS BEING MOVABLE AND PIVOTALLY LINKED TO SAID STATIONARY JAW IN A SCISSORSLIKE MANNER, ROTATING CAM MEANS, ROCKING LEVER MEANS ACTUATED BY SAID CAM MEANS, AND RECIPROCATING ROD MEANS OPERATIVELY CONNECTING SAID ROCKING LEVER MEANS AND SAID MOVABLE JAW, THE IMPROVEMENT WHEREIN SAID LEVER MEANS COMPRISES A BEARING SPINDLE, TWO COOPERATING LEVER ARMS SUPPORTED ON SAID SPINDLE, FIRST HELICAL SPRING MEANS DISPOSED AROUND SAID BEARING SPINDLE AND RESILIENTLY INTER- 